1. Field
The subject disclosure relates generally to wireless communications, and more specifically to calibration techniques for devices operating in a wireless communication system.
2. Background
Wireless communication systems are widely deployed to provide various communication services; for instance, voice, video, packet data, broadcast, and messaging services may be provided via such wireless communication systems. These systems may be multiple-access systems that are capable of supporting communication for multiple terminals by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, and Orthogonal Frequency Division Multiple Access (OFDMA) systems.
A phase-locked loop (PLL) circuit is often an important component of a device that is designed to operate in a wireless communication system. The performance of a PLL can depend on several factors. For example, the loop bandwidth of a PLL can impact the transient response, integrated phase noise (IPN), residual phase noise (RPN), inter-carrier interference (ICI), and other performance parameters of the PLL. To achieve optimal performance for a PLL, the loop bandwidth of the PLL should be well controlled. Therefore, it is often important to place careful controls on the loop bandwidth.
Unfortunately, the loop bandwidth can be affected by many parameters that are often parasitic and variable in nature as a result of process variations. Reasons for these variations include semiconductor process variations, external component variations, and power supply variations. Conventionally, the loop bandwidth of a PLL is controlled by controlling variations of each element or block of the PLL during construction of the PLL. Often, however, this is a complex and unreliable process. Consequentially, there is an unmet need in the art for efficient and reliable techniques for calibrating the loop bandwidth of a PLL.